Electric switch



July 8, 1941. A. w. PLENsLl-:R

ELECTRIC SWITCH Filed April -ll, 1938 2 Sheets-Sheet 1 July 8, 1941. A. w. PLENSLER 2,248,510

ELECTRIC SWITCH Filed April 11, 1958 2 Sheets-Shea?I 2 AX n A Hmmm Patented July 8, 1941 ELECTRIC SWITCH Alexander W. Plensler, Chicago, Ill., assignor to Belmont Radio Corporation, a corporation oi.'

Illinois Application-April 11, 1938, Serial No. 201,385

12 Claims.

My invention relates in general to electrical control apparatus for a radio receiver, and, more particularly is related to my copending applications, Serial No. 390,064, iiled September 3, 1929 (now Patent No. 2,114,068, dated April 12, 1938), and Serial No. 175,001, filed November 17, 1937 (now Patent No. 2,208,549, dated July 16, 1940).

Although electrically operated automatic tuning devices for radio receivers have certain advantages over mechanically operated automatic tuning devices for a similar purpose, in the actual energy required for actuation by an operator, and from the standpoint of control from a position spaced from the radio receiver at either a relatively short distance or great distance, there have been certain disadvantages over the mechanically operated tuning devices in respect to their cost, and their lack of compactness. Furthermore, with some of the prior art electrically operated tuning devices, it has been diiiicult to operate the device to consistently provide peak tuning fory a particular station. These problems were quite satisfactorily solved by the structure of they above noted copending applications. 'I'he present application is concerned with inventions which comprise further satisfactory solutions oi' these problems.

According to the present invention, an electrically operated automatic tuning device is provided with a push button for initiating movement, either manually or electrically, of a contact element comprising a pair of insulatingly separated` contact lingers for simultaneous movement into engagement with a control memberI mounted on a rotary shaft. The control member is provided with a pair of segmental flanges extending in opposite directions from complementary peripheral portions thereof so that each flange extends over slightly less than 180 of the periphery of the control member. The oppositely extending anges which are substantially complementary with reference to one another, define the inward limits of movement of the contact element and consequently the contact fingers, but with the control member in a rotary position rather than in stop position corresponding to a predetermined station setting, only one of the two fingers initially Will engage a flange. 'I'his nange is of course in the path Aof movement of that ringer. A power device is provided for rotating said control member which has a pair of oppositely directed windings for reversible operation of a drive shaft, and a finger is electrically connected to each winding. The control member is connected to a conductor common to both windings. An energizing circuit for the power device is then completed through the linger engaging the control member ilange and lthrough such control member to an actuating winding, the direction of rotation oi the power device depending upon the finger and flange engaged.

A stopping portion is provided on the control member at two contiguous ends of the anges and the rotationof such control member continues until both contact fingers are in registry with a stopping portion of the control member. At this point the power device is rendered inoperative to rotate the control member.' Projecting portions on the ends of the contact iingers engage in the stopping portion of the control member to mechanically stop rotation of such control member at a very deiinite predetermined position. This contact elernent and control member structure is duplicated ordinarily in a number of similar assemblies to provide for the tuning to a plurality of predetermined station settings.

In the present invention, a simplified, compact, electrically operated radio tuning apparatus is provided for direct operation by a manually operable push button or for indirect operation by a push-button switch.

A further feature of my invention is the provision of an electrically operated tuning device which is composed primarily of stamped out, lowcost parts, which may be very quickly and easily assembled into a compact, sturdy device. y

In one embodiment or the invention a simpliiled power means is provided in combination with simplified control structure and together they accomplish electric tuning atlthe radio receiver or a remote point with a minimum number of inexpensive parts, and in an extremely compact and sturdy mechanism.

The invention provides for easy setting of the control members to predetermined station positions without the use of tools or the like, and with thecontrol members in set positions, provides accurate and dependable tuning rapidly and consistently.

The objects and advantages of the invention are for the most part apparent from the foregoingA discussion, but further objects and advantages Will be evident from the following description taken with the drawings, in which:

Fig. 1 is a front elevational view or the complete tuner assembly including a driving motor and a variable condenser to be adjusted by the tuner.

Fig. 2 is an end elevation of the structure of Fig. 1 with a fragmentary illustration of a front panel or escutcheon plate for a cabinet in which the tuner is mounted, but without the combination manual tuning and friction varying knob of Fig. 1.

Fig. 3 is a fragmentary detailed view illustrated in section as along the line 3-3 of Fig. 2 and including a section of the knob.

Fig. 4 is a schematic illustration of a modified embodiment of my invention including the actuating circuit therefor from both an adjacent and a remote position.

Fig. 5 is a schematic illus-tration of the structure and circuit of the embodiment of Figs. l

to 3. v

Fig. 6 is an enlarged detail view of a fragmentary portion of the control member and contact finger structure of Figs. 1 to 3, and Fig. 5. This control member may also be substituted for the control member in Fig. 4.

Fig. 'l is a plan view partly in section along the line 'I-'I of Fig. 6.

Fig. 8 is an enlarged detail view in section along the line 8-8 of Fig. l.

Fig. 9 is an enlarged det-ail view similar to Fig` 6 of a modification of the control member. This modification may be substituted either in the structure of Fig. l or Fig. 4.

Fig. 10 is a fragmentary detail view in perspective of a modification of the actuating portion of the motor of Fig. 4.

Although the form of the invention illustrated in Fig. 1 is shown in conjunction with the usual tuning condenser, it is understood that this form as well as the other forms of the invention, as will be hereinafter described, may be employed with any desirable resonance frequency changing means. The embodiment of Fig. 1 includes a tuning condenser I0 with the variable portion thereof secured directly to a rotary shaft II j-ournalled in a U-shaped frame I2, to one end of which the condenser I0 is rigidly supported. The angular adjustment of the shaft I I, and consequently the tuning position of the resonance frequency changing means is controlled by a plurality of identical control members or rotors I3 on such shaft which are normally frictionally retained against rotary or longitudinal movement relative thereto. Each control member or rotor I3 comprises a one-piece stamped-Out metal member having a disc-like body portion I4 and a pair of segmental anges I6 extending laterally, and opposi-tely relative to one another, from substantially complementary peripheral portions of the body I4. Each fiange has a 'shoulder portion I`I at each end thereof, and with each flange extending slightly less than 180 on the periphery, a notch-like rotor stopping portion, indicated generally by the reference character I8, is provided at two contiguous shoulder portions of the iianges. With the cooperation of the two contiguous shoulders I'I at a stopping portion I8 of the rotor, any circuit through the rotor is broken and mechanical stopping of the rotor is accomplished by the movable contact element for the rotor, as will be more fully described hereinafter.

Each of the rotors I3 is electrically common to the rotary shaft II which in turn is electrically common to a source of current such as I8 which may be either a battery, or other source of direct current, or it may be an A. C. source. The current supply in turn is connected to a lead 2I of a reversible motor 22, which lead ls common to the two fields 23 and 24 of the motor. As is understood, energization of one field will effect clockwise rotation of the motor while energization of the other field will effect counterclockwise rotation. The circuit through a control member and one field or the other is completed by contact means including a pair of identical selector fingers as 26 in connection with the motor field 24, and finger 2'I in connection with the motor field 23. These fingers are each one of a plurality of identical fingers provided in a comb-like conductor 28 for the fingers 28, and conductor 29 for the fingers 21. The combs 28 and 29 are rigidly secured to the front plate 3| of the frame I2 and are insulated from such frames and from one another by means of a pair of insulating plates 32 and 33 respectively. This mounting is accomplished by means of rivets or the like 34 extending through the frame plate. combs, and insulating members as shown in Fig. 8. IInsulating bushings 35 and associated washers insulate the rivets so that there is no shortcircuiting between the combs at the mounting portions.

The selector fingers 26 and 21 are each provided with substantially V-shaped projections 26 and 2l' respectively at the top thereof. The bodies of each of the fingers 2E and 2`I are yiel'dable so that they may be pressed toward a rotor member I3 by means of a manually depressible button 38 slidable in an appropriate guide slot 38 in an escutcheon plate 4I, and a corresponding aperture 42 in a frame plate 43. The button 38 (Fig. 7) is provided in an insulating material, preferably molded, and includes a shank 43 which may be square, or of some other configuration so as to be maintained in apertures 39 and 42 against rotation. A head 44 is provided on the shank wide enough to extend across two adjacent fingers 26 and 2`I. A pair of guide channels 4i are provided in the face of the button head for receiving the two fingers just below the finger projection port'ions 2B and 21 as shown in Fig. 2, to maintain such portions in alignment with their respective fiange portions on the rotor, and also prevent twisting of the body portion of the fingers to take them out of such alignment when a considerable pressure is exerted against the fingers by the button 38.

Each pair of selector fingers 26 and 21, in consecutive pairs from one end or the other of the tuning device as viewed in Fig. 1, together with a corresponding button 38 comprise the movable contact element for a rotor I3. As can be understood from a consideration of Figs. 2, 5, 6, and 7,*particularly, the two fingers 28 and 21 on ltheir combs 28 and 28, respectively, are pushed inwardly simultaneously 'by the manual movement of the selector button 38 available at the front of the radio receiver. The fingers are urged inwardly un'til one or the other of the projections 28 and 2I' engage a flange I6 which yis in the path of movement of a finger by reason of the angular position of that particular control member I3 at that particular time. With the control member I3 in the position shown in Fig. 5, for instance, projection 26 engages a flange I6 and a circuit is completed through the control member I3, conductor 4`I common thereto, source of current supply I8, and conductor 48 to the common lead 2l of the motor 22. The

circuit extends further, through the winding 24 of the motor, conductor 49 extending therefrom, and through the comb 28 and consequently the selector finger 26. V Y

Themotor energizing circuit as described above and illustrated in Fig. is maintained by manually .pressing the button 38 and hence the finger 26, against the rotor flange until the rotor has moved to an angular position corresponding to that shown in Fig, 6. In this position the projection 26 has Just passed ofl of the shoulder I1 for the flange .I6 to break the energizing circuit. The fingers 26 and 21 both under pressure from the pressure on button 38 continue to move inwardly and the projection 26' engages at its lower leg, the periphery of an insulating roller 5I mounted on a stud 52 in a position with reference to the adjacent shoulder I1, such that such projection is carried further away from such shoulder. In this position the periphery of the roller and the lower leg of the projection act as cams and with continued pressure on the button the rotor is actually rotated manually until the two projections 26 and 21' seat completely as shown in dotted lines in Fig. 6, with the lower leg of projection 26' wedged against the one roller 5I, and the projection 21' wedged at its upper leg against the other roller 5l, shown dotted. The motor circuit is oi course broken during this manual rotation and the shaft Il is declutched therefrom, as will be explained. The positions of 4the iinger projections and corresponding buttons in non-operat'mg `position and iinal tuned position are shown in Fig. 2. The iront contact unit or element is in tuned position, while the unit behind this is in non-operating or idle position.

A modification of this rotor structure is illustrated in Fig. 9. A stationary insulating plate 5I is rigidly secured on each side of the rotor body it at a position relative to its corresponding ilange shoulder I'I such that a cam surface 50 acts with each finger projection to cause the final rotational movement oi the rotor to cause the projections to completely seat in the ilnal tuned position.

In. the structure of Figs. l to 3, and 5, the shaft Il .is connected to the motor '22 through intermediate gears including a pinion gear E2 on a bushing or the like, gear 53 on a stud shaft 5t, and this also has secured thereto apinon gear 56 in engagement with the driven gear tf1. The latter is secured to a collar or bushing 56 which is keyed on the shaftv il against rotation with reference thereto, but which is longitudinally slidable so that the entire rotor assembly may be moved longitudinally to vary the friction on the individual rotor members. The pinion gear 52 is connected with the armature shaft 59 by a simple mechanical clutch mechanism which includes an arm 6l secured to such shaft and a corresponding arm 62 secured to the pinion gear 52 and arranged so that when the armature is drawn. in a longitudinal direction into the field of the motor windings, the arm 6I engages the arm 62 and rotates the same therewith so long as a motor winding is energized. The motor 22 itself is a commercial product which is no part of the present invention, and it is understood that this is merely one convenient form of driving power. As to the intermediate driven shaft 54, this is provided with an extension outwardly from the tuner frame as shown in Figs. 1 and 3 to accommodate appropriate gearing for a right-angled drive to be operated manually from the front of the tuner if it is desired to substitute such a device for the manual movement of the shaft II by means of a knob 63 secured directly on the shaft II.

'I'he frictional pressure on the rotors I3 is varied, and the setting of such rotors to angular positions corresponding to predetermined station frequencies is accomplished by mechanism including the knob 63 supported on the shaft II so that a lug (not shown) on such knob at the shank is keyed in a key-way 64 of the shaft against rotation relative thereto. This structure is fully described and claimed in my copending application, Serial No. 170,070, filed October 26, 1937. The shank of the knob 63 engages a bushing 66 for carrying the shaft I I journalled in the end plate 1I of the frame and is movable to move the entire rotor assembly including the bushing 58 and associated gear 51, friction washers as 6l, and spacing collars 68, against stop means at the other end of the shaft. The movement of the knob and the rotor assembly as described, is effected by screwing a cap screw 68 onto the threaded end 'II of the shaft II. rEhe head of the cap screw engages a shoulder l2 in an external cavity of the knob. Similarly, the friction on the individual rotors is reduced by' unscrewing the cap screw 69 thus permitting a loosening of the individual parts of the rotor assembly so that the shaft II may be rotated independently of the rotors. With the friction sufficiently reduced on each rotor, such rotors are set to a predetermined station position by the operator pressing a selected button 38 inwardly until one of the two iingers being moved by said button engages a ange I6 of the corresponding rotor. rThis engagement energizes the motor 22, as described above, to drive the shaft il and rotor engaged until the motor circuit is broken by the engaged finger passing oil of the flange, at the stopping portion i8. With continued pressure on the button the projections 26 and 2T of the fingers are seated in their final position, as shown in the dotted lines of Fig. 6. With the selected button 33 still depressed to lock the corresponding rotor it against movement, the shaft il is rotated by the knob 63 or similar device, lrey'ed to said shaft, and by watching a suitable indicating scale operating with the shaft, the operator can detera mine when the angular position of the shaft Il and condenser I0 corresponds to the setting for the station desired. inasmuch es there is always suicient frictional pressure `on the rotors i3 to prevent them from rotating loosely relative to the shaft, this setting operation may be followed for all of the rotors I3 in order, without disturbing the position of rotors previously adjusted. This pressure, of course, is also suicient to maintain each rotor sufliciently fixed on the shaft to permit its rotation with the shalt il while the motor is driving the shaft to bring the rotor to stopping position. In this manner the entire tuning device may be set up while the friction is off, for predetermined tuning of a number of stations corresponding to the number of rotors, and after all of such settings have been completed, the friction may then be applied to the rotors by turning the cap screw 69 onto the threaded end 1I of the shaft, as has been described.

Another form of the invention is illustrated schematically in Fig. 4. Only a single rotor with its associated button and finger contact mechanism is illustrated, but itis understood that the rotor assembly and its associated shaft is similar to that of Figs. 1 to 3 and may be substituted in the frame I2 for the other rotor assembly. Similarly, the conductor combs with the selector fingers integral therewith are mounted on the front of the frame as illustrated in Figs. 1 and 2. For convenience in following the description of the embodiment of Fig. 4 the parts illustrated in Fig. 4 identical with such parts in the structure of Figs. 1 to 3 will bear the same reference characters. Parts in the embodiment of Fig. 4 which are similar to parts in the embodiment of Figs. 1 to 3, yet modified, will bear the reference character originally applied but prefixed by the numeral I. As illustrated, the embodiment of Fig. 4 is provided for remote or indirect tuning where the contact fingers are actuated by electrical means as contrasted to the movement thereof directly by manual operation of a push button, as well as being provided for such manual operation. It is understood that the embodiment of the invention illustrated in Figs. 1 to 3 and Fig. 5 can be similarly equipped for indirect tuning by the means disclosed in Fig. 4.

The structure illustrated in Fig. 4 comprises a one-piece rotor H3 with integral flanges IIS each extending in opposite directions from the portion H4, at the periphery of segmental portions of such rotor. A shoulder H1 is provided on each fiange, and the two shoulders in contiguous positions are positioned at a stopping portion H8 positioned similarly to that of rotor I3. However, the fianges II6 are both slightly longer than the flanges I6 so that the finger projections 26 and 21' actually 'engage such contiguous shoulders in the final set position of the rotor rather than being spaced therefrom by insulating members as I and 5I. The finger projection 26 is illustrated in its final set position in Fig. 4. The projection 21 is of course to the back of the projection 26 and not visible` in the elevation as illustrated but is in the identical inward position. The stopping portion II8 on the'rotor H3 is therefore, so far as it constitutes a stop gap for the finger projections 26 and 21', of slightly smaller area than the similar portion I8 of Fig. 5. The selector fingers 26 and 21 are pressed inwardly toward the rotor, and maintained in alignment with the flanges thereof by means of a button |38 of insulating material appropriately mounted at the frame for the tuner.

The shaft II in Fig. 4 is rotated by means of an electrically operated power device 13 which includes a pair of relays or vibrators mounted on the end portion 14 of the frame I2. Each unit comprises a core 16 having a winding 11 thereon, with a permanent magnet armature 18 mounted on a flexible reed which in turn is mounted at 18. The armature is movable to and away from the core in the usual manner. Mounted on each armature is a substantially sharp-ended prong 19 so shaped and positioned that it will engage the rim 8l of a Wheel 82 supported on the shaft II intermediate the knob 63 and the first rotor II3 as can be understood from Fig. 3. The wheel 82 ismounted on the shaft II in the same manner as a rotor I3 or I I3, with friction washers on each side, and positioned into the assembly at the right end of the shaft (Fig. 3) with spacing sleeves or collars. The wheel 82 may be entirely of rubber or it may merely be providedwith a rubber rim 8|. Other materials to provide a friction surface may be used for the rim 8l. As one armature 18 or the other is vibrated, the corresponding prong 18 engages the rim 8I on its inward stroke, and the wheel 82 is rotated in a step by stem movement. The interval between impulses at the armature and hence between rotative steps is so slight that the interruption of the movement of the wheel 82 and consequently the tuning shaft II is not noticeable. The windings 11 on the magnets extend in opposite directions so that energization of the right-hand magnet, for instance, causes its armature to rotate the wheel 82 in a clockwise direction while energization of the other magnet rotates the wheel 82 in the opposite direction.

Upon pressing the button |38 inwardly, and in the resulting engagement of the projection 28 and its corresponding flange IIE, a circuit is completed which extends through the rotor and shaft II electrically common thereto, conductor 83, through a source of current supply 84 (may be same as I8), conductor 8B, and lead 81 common to both windings, through the left-hand winding 11 and conductor 89 back to the comb for the finger 26. The energized winding 'I1 draws the armature 18 thereto, with the frequency of vibration of such armature corresponding to the impulse frequency of the current supply. It is understood that the vibrator unit will operate on either A. C. or D. C. The structure is illustrated as constructed for A. C. energization, but it is necessary merely to add Contact points at the armature in the well known manner to get a vibratory motion with D. C.

energization.

The rotation of shaft II continues until both finger projections 26' and 21' are in registry with a stopping portion II8 on the rotor. At this point as a result of the inwardly directed pressure on the button I38, the projection 26 passes inwardly over a shoulder II1 at the lower leg of such projection and simultaneously therewith the projection 21' is likewise moving inwardly until the upper leg of such projection engages a corresponding shoulder II1 of the rotor. This is the position illustrated in Fig. 4 with both finger projections in engagement with contiguous shoulders Ill. At this position .the circuit described above is maintained through finger 28, and with the projection 21 likewise in engagement with a flange, a circuit is completed through the right-hand electromagnet illustrated in Fig. 4. This circuit extends from the rotor H3 through the shaft II and conductor 83, through the current source 84, and conductor 86 connected to the common lead 81, through the right-hand winding 11 and the conductor I8 back to the comb for the finger 21. This causes a short circuit through both fingers 26 and 21 and their corresponding electromagnets. Under this condition both electromagnets are energized and each armature continues to vibrate, to in turn cause engagement by both prongs 18 with the rim 8I of the driving wheel. This prevents the wheel from rotating in either direction. In the meantime, with the finger projections 26' and 21 seated fully against their respective flanges I I1 under the pressure of the button |38, the rotor II3, and consequently the shaft II is securely locked against rotation.

When setting the rotors H3 .to predetermined station positions vthe friction on such rotors is reduced in the manner described for rotors I3. With the wheel 82 retained on the shaft I I under the same frictional pressure as the rotors, such wheel will drive the rotors selectively to a position at which projections 26' and 21 engage their corresponding ilang'e shoulders ||1. One windlng 11 or the other is, of course, energizedas soon as anger projection engages a ilange. The selected rotor is then locked in position while the shaft is rotated to the desired angular position. During this time both magnets oi' the motor are energized and the wheel is effectively held against rotation. However, the shaft cani be turned in the wheel in the same manner it can be turned in the rotor, with the latter stationary. With the system of Fig. 4, a magnetic clutch can be provided to break the energizing circuit upon the short circuit/ing of the lingers 26 and 21 in the same way the circuit is broken when two insulated rotor portions are shorted as described in the above mentioned pending applications.

The effectiveness of the motor 13 may be further increased by a modiilcation of the magnet structure as shown in Fig. 10. In this embodiment the core 16 is secured to a metal bracket 9| stamped out of the end plate 14 of the frame bracket while a lug 92 is similarly stamped out of the end plate at a position so as to be only slightly spaced from the upper end of the core 16. With this construction the magnetic path for the magnet extends through the lug 92, the end portion 'il of the frame and the bracket 9| back to the core it. The polarity of the core and lug at the .gap changes and alternates with each 1/2 cycle, and on one 3/2 cycle the armature 18 is repulsed instead'of attracted so it vibrates toward the Wheel 82 just haii' as many times as with the structure of Fig. 4.-. The magnetic path through the core is likewise shortened with this construction to provide greater driving eiiiciency. Furthermore, there is no necessity for a metal reed for the armature and this can be of any desired material. Slowing down the movement of the armature andreed causes more elcient application of the force of the prong 19 on the rim Sil ci the wheel and provides a greater driving force on the rotary shaft although a slower movement. The time required for tuning is still so small that the reduced speed of rotation would not be noticeable to an operator and yet all of the advantages of greater driving force. and also reduced noise of operation make the use of this driving structure exceedingly satisfactory.

ln order to operate each pair of fingers 2E and 2l from position remote from the radio receiver or operate such fingers when they are mounted in a radio receiver cabinet at a position such that direct :manual movement by a button is not practical, I provide an eiectromagnet 93 insulatingly mounted on an extension 9B from the plate 3|. The magnet; is connected in a circuit including the source of current such as applied at 8l or some other source of current as will be explained. Such source is illustrated schematically at S in Fig. 4. The circuit also includes a push button switch d of any desirable construction, and a conductor 95 intermediate the button 9| and a winding for the magnet. The core of the electromagnet 93 includes an extension 91 against which the armature 98 is drawn when the magnet is energized. TheV ilexible arm or reed 98' carrying the armature 98 has a forked extension on the Itop thereof which s traddles the shank |43 of the button |38 at a channel 99 in such shank so that the reed 98 will move upon movement of the button |38 and vice Versa. When the electromagnet 93 is energized upon closing of the button switch 94, the armature 98 will be attracted to the core extension 91 to move the button |38 and in turn move the fingers 26 and 21 toward the corresponding rotor H3.

'Ihere is normally a source of direct current supply in a radio receiver, either as the main current supply for the receiver in the case of a lD. C. receiver, or as a converted D. C. supply in the tube circuit in the case of the usual receiver operated directly from A. C. If the tuning device including a remotely controlled portion as just described is constructed for D. C. energizetion of the electrcmagnet 93, the reed 98' and the core extension 91 may be so dimensioned and positioned that when one of the iinger projections 28' or 21 is merely riding on a flange ||6 there is a slight air gap between the armature 98 and the extension 91. With the button 94 held depressed during the tuning operation the magnet 93 is of course constantly drawing the amature 98 thereto, and when either one or the other of the linger projections slides over the shoulder H1 of an engaged flange HS the gap between the armature 98 and extension 91 is closed and the two finger projections seat against their respective flange shoulders as previously described providing such an air gap between the extension @l and armature 98 is not ordinarily practical 'when energizing the magnet 93 with alternating current because or" the chattering which occurs. However, it is probably somewhat preferable to use A.. C. supply at the point S in the circuit and supply .the electromagnet 93 with the usual shading rings. With this construction thereed 98' and extension 91 are so positioned that the armature 88 abuts the extension @l when a finger projection is riding on a dange HG. The portion of the reed t8" intermediate the armature S8 and tile button shank H3 is provided flexible enough and oi' auch shape that it is bowed outwardly and under tens-ion when a ringer projection 26 or 2l is riding on a flange. When such projection arrives at the stopping portion on the rotor the spring pressure of the reed itself will urge the button inwardly and thus seat the ringer projections in final locking position.

it is understood of course that the power device illustrated in Figs. i and l0 can be substituted for the motor 22 described in connection with the structure ci Figs. Il to 3 and 5. iin fact, this ypower device has particular advantages in the complete tuning system of my invention, in that the driving wheel of the motor may be mounted directly on the rotary control shaft without any reduction gearing, thus simplifying the driving structure and greatly reducing the cost thereof. The motor operates with considerable driving force, and with little noise, so that eiiicient, quiet tuning is provided. In addition no supplementary clutch is required, thus further reducing the complexity of the driving mechanism as well as the entire tuning device as a whole, and of course reducing the cost of the same. lin the tuning apparatus as a whole it is apparent from the above description that I have provided an extremely simple and inexpensive device for direct push button operation for indirect control so that the tuning device may be adapted to any possible radio receiver construction and installation requirements.

Although the invention has been illustrated and described in its preferred embodiments.' itA 1. Electrical control apparatus for a radio receiver including in combination a rotary shaft, a plurality of rotatable conducting discs on said shaft for determining control positions of the shaft, each of said discs having two substantially complementary peripheral portions together extending over substantially the 360 of the periphery of such disc, a lateral flange at each peripheral portion With said flanges extending in opposite directions relative to one another and each flange having a shoulder portion at each end thereof with a disc stopping portion at two of said shoulder portions adjacent to one another, a manually operable push button corresponding to each of said discs, and movable contact means having stop means at the end thereof movable upon depressing oi' its corresponding button to engage one flange or the other of a corresponding disc to complete a circuit through said flange with the stop means of said contact being in registry with a disc stopping portion at a. control position of the shaft.

2. A control device for a radio receiver including a stoppable rotatable control member of conducting material having a pair of flanges extending laterally at the periphery thereof, oppositely disposed as to one another and each extending over substantially complementary portions of the periphery, movable contact means including a pair of adjacent contact fingers insulated from one another but simultaneously movable toward said control member until one or the other engages the outer surface of a peripheral flange, and with such engaging finger being oil.' the outer surface of the engaged flange at an end thereof when the control member is in stopped position.

3. Electrical control apparatus including a conducting disc rotatable to a predetermined position having a pair of lateral flanges at complementary peripheral portions thereof extending in opposite directions from the body of the rotor, a pair of contact fingers in alignment with said disc insulated from one another but movable simultaneously toward said disc with one of said fingers engageable with one of said flanges on a surface of said one flange while the other finger ls out of engagement with a flange, with said linger engaging the flange being off the surface of such flange when the disc is in a predetermined position.

4. Electrically operated apparatus for controlling the angular movement of a. shaft including in combination a rotary shaft, a plurality of control discs on said shaft in engagement therewith and each acting to stop the rotation thereof at a predetermined position, each of said discs having a pair of complementary segmental conducting portions with a flange extending laterally at the peripheral edge of each portion and in opposite directions with reference to one another, said flanges each having a shoulder at the ends thereof with contiguous shoulders of the two flanges forming a disc stopping portion, and a contact element corresponding to each disc comprising a pair of yleldable selector fingers insulated from one another but movable together, with one or the other of such fingers engageable with a disc flange in alignment therewith to complete an electric circuit through the disc.

5. Radio tuning apparatus including in combination a rotary shaft, a one-piece conducting disc on said shaft having a pair of peripheral flanges substantially complementary but extending in opposite directions relative to one another, with each flange having a shoulder at one end and said shoulders adjacent one another, selector means spaced outwardly from the periphery of the disc and movable toward said periphery comprising a pair of insulatingly separated contact projections, and one or the other of said projections adapted for engagement with a corresponding flange on said disc, with each of said contact projections being movable inwardly of the engaged flange at said shoulders.

6. Radio tuning apparatus including in, combination a rotary shaft adapted to rotate the predetermined tuned positions, a conducting disc on said shaft including a body portion and a pair of peripheral flanges substantially complementary but extending in opposite directions relative to one another, with each flange extending less than 180 on said disc and each having a shoulder at one end adjacent one another but angularly spaced from one another, insulating means on said body portion on each side thereof positioned radially from an adjacent ange shoulder and angularly spaced relative to one another less than the angular spacing of said shoulders, selector means for movement toward said disc for initial engagement with one flange or the other with said selector means being in engagement with said insulating means on both sides of said body portion at a predetermined tuned position of the rotary shaft.

7. Radio tuning apparatus for tuning to a predetermined position including in comblnation, a rotatable control member having a pair of peripheral flanges substantially complementary but oppositely extending relative to one another, a selector element comprising a pair of separated fingers for movement toward the periphery of said member, an insulated member for engaging both fingers to move them simultaneously, electromagnetic means adjacent said insulated member having a movable armature member connected with said insulated member to move the latter upon energization of said electromagnetic means to urge said fingers toward said control member and bring one finger or the other into engagement with a flange, with said fingers both being in substantial registry with adjacent ends of the two flanges at a predetermined tuning position of the apparatus.

8. Selector mechanism for controlling the tuning of a radio receiver including in combination. a rotary unit having a plurality of control units thereon, a pair of conductor combs with each of said combs including a plurality of contact fingers thereon and each comb being insulated from the other comb, means for supporting said combs in a position with respect to one another and said rotary unit such that each control unit has a pair of contact fingers in alignment therewith, with each finger in said pair being in a different comb, and means engaging a selected pair of contact fingers and movable toward the corresponding control unit to bring one finger or the other in the pair into engagement with said control unit.

9. Selector mechanism for controlling the tuning of a radio receiver including a rotary conductor disc, said disc having a pair of substantially complementary and oppositely extending peripheral flanges, each flange having a shoulder at one end thereof with said shoulders being angularly displaced on said disc with respect to one another, a pair of insulating rollers supported on said disc adjacent said shoulders, extending oppositely and angularly displaced with respect to one another, such displacement being less than the angular displacement of said shoulders, and a pair of insulatingly separated contact lingers corresponding to the two flanges and two rollers movable simultaneously toward said conductor disc to engage one flange or the other in one position of the disc, with each finger being in engagement with its corresponding insulating member on said conductor disc in another position of the disc.

10. Selector mechanism for controlling the tuning of a radio receive including a rotary conductor disc, said disc having a. pair of substantially complementary and oppositely extending peripheral flanges, each ange having a shoulder at one end, and said shoulders being adjacent one another but angularly displaced on said discI a pair of insulating members secured to said disc on opposite sides thereof at said shoulders with each member having a beveled portion thereon and with said beveled portions being oppositely positioned and angularly displaced with respect to one another, and a pair of insulatingly separated contact fingers corresponding to the two iianges and two members movablesimultaneously toward said conductor disc to engage one flange or the other in one position of the disc with each finger being in engagement with its corresponding insulating member at said beveled portion in another position of the disc.

11. Selector mechanism for controlling the tuning of a radio receiver including a rotary conductor disc having a pair of substantially compiementary and oppositely extending peripheral flanges with an end of each flange being adjacent to one another, a selector unit comprising a pair of adjacent but insuiatingly separated contact fingers for movement toward the periphery of said disc, electromagnetic means adjacent said contact fingers and operatively connected therewith for moving said fingers simultaneously toward said conductor disc to bring one finger or the other into engagement with a peripheral flange at one position of the disc and with both fingers substantially in registry with the adiacent ends of said flanges at another position'of the disc.

12. Electrical control apparatus including a control disc rotatable to a predetermined control position, said disc including a pair of complementary peripheral conducting portions electrically common and extending in oppositely disposed directions Irom a radial plane through the disc, with a stop portion at contiguous ends of said conducting portions, contact means including a pair of contact portions insulatingly separated, with each contact portion in radial alignment with a corresponding conducting portion, movable insulating means engaging both contact portions to simultaneously move both contact portions toward said disc to engage lone contact portion and one conducting portion in one position of the disc. and with said contact portions and said disc stop portion being in alignment in another position of the disc.

ALEXANDER W. PLENSLER 

